Following are the principal studies to be undertaken as part of a long term-project on the factors underlying the presence of cutaneous leishmaniasis in Panama: 1. Search for natural leishmanial infections among both feral and domestic Panamanian mammals. 2. Experimental infection of laboratory-bred forest rodents with Leishmania braziliensis and L. mexicana, Sasardi strain, to determine their susceptibility as well as the nature and course of the infection in each of them. 3. Colonization of forest mammals which have been found with natural cutaneous leishmaniasis elsewhere in the New World. 4. Characterization of Panamanian dermatropic species and strains of Leishmania. 5. Xenodiagnostic studies using laboratory-reared phlebotomine vector species to isolate Leishmania braziliensis from the principal reservoir host, Choloepus hoffmanni. 6. Host-preference investigations using a variety of Panamanian mammals to judge their attractiveness to vector and potential vectors of Leishmania. 7. Attempts to establish colonies of additional phlebotomine species in our insectary.